I purchased it as part of Macheist and honestly I'M bot that impressed with it so far: It's got a syntax highlighting, FTP support and a list of your CSS tags... and that's about it.

Apart from that it doesn't really bring any new features to the table that Coda doesn't have. I realize it's also a bit cheaper, but if I was going to spend that much on an app, I'd want a real improvement in my workflow, which I'm not really seeing with Espresso - yet. But I'm not a heavy user of this type of app either...

So for the time being I'm sticking with my Transmit / Subethaedit combination.